The present disclosure provides a simplified and reliable construction for a high-pressure rotating water jet nozzle which is particularly well suited to industrial uses where the operating parameters can be in the range of 1,000 to 40,000 psi, rotating speeds of 1000 rpm or more and flow rates of 2 to 50 gpm. The present disclosure in particular is directed to such a nozzle that has rotary speed control so as not to rotate at very high speeds.
A typical high pressure rotary water jet nozzle is offered by StoneAge Inc. known as the “Banshee” nozzle. This nozzle is described in some detail in our U.S. Pat. Nos. 7,635,096; 8,006,920 and 8,016,210, among others. During pressurized operation of the nozzle, axial forces on the tubular shaft reach equilibrium minimizing axial contact between the tubular shaft and the housing body. Also, the tubular shaft member is thereby supported within the housing body entirely by fluid between the shaft member and the housing body. As a result, this nozzle typically can rotate at speeds as high as 40,000 rpm. Such speeds may be fine for small tube operations, such as heat exchanger tubes, where the speed of the nozzle jet moving across the surface or wall of the tube may be in a range of 50 to 100 feet per second. However, it has been shown that speeds along a surface faster than about 60 feet per second tend to show deterioration of jet impact. Hence there is a need for a slower speed rotary water jet nozzle in which rotational speed is more limited so as to effectively deal with hard to remove deposits/materials in piping systems.
A prior art nozzle as disclosed in U.S. Pat. No. 8,016,210 is shown in
Before the development of the type of nozzle described above, controlled speed nozzles required bearings submerged in viscous fluid, separated from the working fluid by high pressure seals. Such tools rotated in the range of 500-1000 rpm when new, but degraded relatively quickly during use and therefore such tools needed frequent maintenance which made such configurations very expensive to operate and maintain. Further, there was a limit on how small such nozzles could be made using bearings etc.
Large tube cleaning can alternatively be done with nozzles that utilize magnets and eddy current braking for speed control. However, such nozzles require bearings and seals, again adding to the initial and ongoing maintenance cost of such nozzles. Against this backdrop, what is still needed is a simple nozzle that can be speed controlled without the need for bearings, viscous fluid, or magnetic brakes, etc.
This disclosure addresses this need. One embodiment of a nozzle assembly in accordance with the present disclosure is a water bearing rotary nozzle for use in a high pressure (HP) range of up to 40,000 psi having a “straight through” fluid path to a jet head at a distal end of the nozzle assembly where the head is preferably capable of providing rotating fluid jet coverage, which includes a speed reduction mechanism. A nozzle assembly for spraying high pressure fluid in accordance with the present disclosure is specifically designed to spray the fluid against an object such as an internal wall of a heat exchanger tube. In a typical nozzle assembly of this disclosure, the internal forces resulting from such operating pressures tend to create an axial thrust force acting against the rotating nozzle shaft within the nozzle body with a force corresponding to the operating pressure and cross sectional area of the shaft.
A nozzle assembly in accordance with the present disclosure also provides a straight-through fluid path in which the pressure of the operating fluid is allowed to reach and act upon opposing surfaces of the rotating nozzle shaft so as to effectively balance any axial thrust force. This is accomplished by providing a “bleed hole” to allow a small portion of pressurized fluid within the rotating nozzle shaft to reach a chamber or channel within the housing but outside the exterior of the forward portion of the nozzle rotary shaft member where the fluid pressure can act upon the nozzle shaft member with a sufficient axial component so as to balance the corresponding axial component against the nozzle shaft created by the internal fluid pressure. This chamber or channel communicates with the exterior of the device by means of a slightly tapered frusto-conical bore in the nozzle body surrounding a corresponding tapered portion of the rotating shaft member providing a tapered frusto-conical gap defined between the tubular shaft member and the cylindrical housing body which further allows the fluid to flow between the body and the shaft to facilitate or lubricate the shaft rotation.
Because of the tapered shape, the spacing between the nozzle housing body and the rotating shaft member varies slightly with axial movement of the shaft and creates a “self balancing” effect in which the axial forces upon the shaft remain balanced and there is always some fluid flowing between the shaft and housing which helps decrease contact and resulting wear between these two components. Due to the lack of any significant imbalanced radial forces and the fluid flowing between the surfaces of the shaft and housing, a nozzle assembly or device of the present disclosure can be constructed without need for mechanical bearings.
Around the inlet end of the tubular rotary shaft member is a centrifugal set of weight segments. These weight segments are rotationally captured with the inlet end of the shaft within the nozzle housing body and are separable outwardly, preferably radially, from between the inlet end of the shaft toward the internal surface of the housing. In one embodiment of the nozzle assembly, these segments are configured to ride along a transverse linear rail machined in the rotary shaft between the tapered portion and the inlet end of the rotary tubular shaft. In one embodiment the transverse linear rail encompasses the central axial passage through the rotary tubular shaft. Each side of the rail preferable has a ridge or rib engaging a complementary slot in each of the weight segments such that segment movement is constrained to move laterally away from the central axis of the shaft along the rib of the rail only as rotational speed of the tubular shaft increases. The weight segments then press against the inner surface of the housing creating a drag force against the housing to slow and limit the speed of shaft rotation.
A nozzle assembly for spraying high pressure fluid against an object in accordance with the present disclosure includes a hollow cylindrical housing body and a hollow tubular rotatable shaft member coaxially carried within the housing body. The rotatable shaft has a fluid inlet end within and near one end of the housing body and an outlet end near a second end of the housing body for securing a spray head thereto for rotation with the shaft. The shaft member has a central passage to conduct fluid from the inlet end to the outlet end. The housing body has a high pressure fluid inlet passage communicating with the central passage of the shaft and the housing body has an inlet bearing area supporting the inlet end of the tubular shaft member. This housing body preferably includes an inlet nut threadably fastened thereto which supports the inlet end of the rotatable shaft member and which in turn is configured to connect to a source of high pressure fluid such as a hose.
The nozzle assembly includes a regulating passage formed between an inner surface of the housing body and an outer surface of the rotatable shaft member and one or more bores communicating, i.e. extending, between the central passage of the shaft member and this regulating passage. Pressure of fluid within the regulating passage acts axially upon the shaft to counterbalance axial force on the shaft exerted by fluid pressure acting upon the inlet end of the shaft. The regulating passage is preferably a tapered frusto-conical gap defined between the tubular shaft member and the housing body. A plurality of partial annular weight segments is disposed between the regulating passage and the housing body and adjacent the inlet bearing area of the housing body and captured between the inlet end of the shaft member and the cylindrical housing body. These weight segments are constrained to rotate with the shaft member but are free to separate outwardly, preferably radially and laterally from the shaft member and press against an inner wall surface of the cylindrical housing body to reduce rotational speed of the shaft member within the cylindrical housing body during nozzle operation.
In one exemplary embodiment, the centrifugal weight segments are preferably two half annular segments disposed on the shaft member adjacent the inlet bearing area of the housing body. During pressurized operation of the nozzle assembly, axial forces on the tubular shaft reach equilibrium, so that there is no axial contact between the tubular shaft and the housing body. Hence, during pressurized operation of the nozzle, the tubular shaft member is supported within the housing entirely by a flow of operating fluid between the shaft and the housing body, and rotation of the shaft is caused by reaction forces generated by high pressure fluid.
A nozzle assembly in accordance with the present disclosure may also be viewed as including a hollow cylindrical housing body and a hollow tubular shaft member coaxially carried within the housing body. The shaft member has a fluid inlet end within and near one end of the housing body and an outlet end projecting from a second end of the housing body. This outlet end is configured to receive a spray head fastened thereto for rotation of the head with the shaft. The shaft member has a central passage to conduct fluid from the inlet end to the outlet end. The housing body has a high pressure fluid inlet passage communicating with the central passage of the shaft member.
An inner wall of the housing body and a portion of the shaft member toward the outlet end of the shaft have complementary tapered surface shapes, together forming a regulating passage therebetween. The shaft member has one or more bores communicating between the central passage through the shaft member and the regulating passage, wherein pressure of cleaning fluid within the regulating passage acts axially upon the shaft to counter axial force on the shaft resulting from fluid pressure acting upon the inlet end of the shaft. The inlet end of the shaft member carries at least a pair of partial annular weight segments therearound captured between the shaft member and the cylindrical housing. These segments are free, i.e. operable, to separate laterally, i.e. move outward radially from the shaft member under centrifugal force, as the shaft member rotates, and press against the inner wall of the cylindrical housing body to reduce rotational speed of the shaft member within the cylindrical housing body during nozzle operation.
The regulating passage in this nozzle assembly is preferably a frusto-conical gap defined between the tubular shaft member and the cylindrical housing body. The volume of the regulating passage varies as the tubular shaft moves axially within the housing body. During pressurized operation of the nozzle, axial forces on the tubular shaft reach equilibrium minimizing axial contact between the tubular shaft and the housing body. Also, the tubular shaft member is thereby supported within the housing body entirely by a fluid film or layer of water acting as a bearing between the shaft member and the housing body.
The shaft member has a feature operable to constrain movement of the weight segments to only toward and away from the central passage through the shaft member during nozzle operation. This feature may include a linear rail extending laterally across the shaft member adjacent the central passage. Preferably this linear rail crosses the central passage through the shaft member. Preferably the lateral straight rail formed in the shaft member between the inlet end of the shaft member and the tapered surface portion of the shaft member extends radially from the central passage. This rail carries on it the partial annular weight segments such that they slidably move outward toward the inner wall of the housing body during shaft member rotation during nozzle operation. These weight segments engaging the inner wall of the housing body during nozzle operation provide a limiting force on rotation of the shaft member and hence limit the speed of rotation. This rail preferably has a constant cross-sectional shape. Each of the segments has a shape complementary to the cross-sectional shape of the rail. Preferably the rail includes a feature such as at least one linear ridge, tab or rib and each weight segment has a groove complementary to the at least one tab or rib to constrain movement of the segment in a radial direction toward or away from the central passage through the tubular shaft member and preclude axial movement of the weight segments along the axis off the shaft member. Finally, the outer curved surface of each of the weight segments may include a plurality of peripheral grooves.
One exemplary embodiment of a nozzle assembly 100 in accordance with the present disclosure is shown in
The tubular shaft member 108 has an axial central passage 114 to conduct fluid from the inlet end 110 to and through the outlet end 112 to a spray head 130, shown in
A regulating passage 118 is formed between the housing body 102 and an outer surface of the shaft 108. In preferred embodiments, the regulating passage 118 is a tapered frusto-conical gap defined between the tubular shaft 108 and the cylindrical housing body 102. One or more bores 120 extend between the central passage 114 of the tubular shaft member 108 and the regulating passage 118. Pressure of fluid within the regulating passage 118 acts axially upon the shaft member 108 to counterbalance axial force on the tubular shaft member 108 exerted by fluid pressure acting upon the inlet end 110 of the tubular shaft member 108.
A plurality of partial annular segments 122 are disposed on the shaft member 108 adjacent the distal end of the inlet nut 104 between the inlet bearing area 116 of the housing body 102 and the regulating passage 118, captured between the inlet end 110 of the shaft member 108 and the cylindrical housing body 102 and constrained to rotate with the shaft member 108. In the exemplary embodiment shown in
Each of the segments 122 slides laterally on a transverse straight rail 124 formed in the tubular shaft 108. This transverse straight rail 124 formed in the shaft 108 includes a feature 128 thereon which prevents axial movement of the weight segments 122 toward the inlet end 110 of the shaft member 108. Preferably this feature 128 is a raised rib or tab extending outward from the rail 124. Each of the segments 122 has a complementary shape feature 130 to engage the rail 124 with its tab or rib feature 128 so as to slide or ride on the rail 124 only laterally, i.e. radially, during nozzle operation.
As the shaft 108 rotates in the housing body 102, contact between the weight segments 122 and the rail 124 causes the segments to rotate with the shaft 108. As the shaft rotates, centrifugal force pushes the segments 122 radially outward, eventually contacting the inner wall of the housing body 102 and providing a drag force against further rotational speed. Some of the high pressure fluid from the regulating passage 118 leaks past and provides some lubrication to the segments 122. This leakage fluid then exits through the discharge ports 126 through the housing body 102.
In the embodiment shown in
Another embodiment of a nozzle assembly 150 in accordance with the present disclosure is shown in
The shaft member 108 has an axial central passage 114 to conduct fluid from the inlet end 110 to and through the outlet end 112 to a spray head 130, shown in FIG. 4. The high pressure fluid inlet passage 106 in the housing body 102 through inlet nut 104 coaxially communicates with the central passage 114 of the shaft member 108. The housing body 102 has an inlet bearing area 116 formed by the inlet nut 104 supporting the inlet end 110 of the tubular shaft member 108.
A regulating passage 118 is formed between the housing body 102 and an outer surface of the shaft 108. One or more bores 120 communicate between the central passage 114 of the shaft member 108 and the regulating passage 118. Pressure of fluid within the regulating passage 118 acts axially upon the shaft member 108 to counterbalance axial force on the shaft member 108 exerted by fluid pressure acting upon the inlet end 110 of the shaft member 108.
A pair of partial annular weight segments 122a are disposed on the shaft member 108 adjacent distal end of the inlet nut 104 and between the inlet bearing area 116 of the housing body 102 and the regulating passage 118 and captured between the inlet end 110 of the shaft member 108 and the cylindrical housing body 102 and constrained to rotate with the shaft member 108, wherein the segments are free to separate laterally from the shaft member 108 and press against the inside wall surface of the cylindrical housing body 102 adjacent the inner, or distal, end of the inlet nut 104 to reduce rotational speed of the shaft member 108 within the cylindrical housing body 102 during nozzle operation.
Each of the weight segments 122a slides laterally on a transverse straight rail 124 formed in the shaft 108 that extends fully across the shaft 108. As the shaft 108 rotates in the housing body 102, contact between the segments 122a and the rail 124 causes the segments to rotate with the shaft 108. As the shaft rotates, centrifugal force pushes the segments 122a radially outward, eventually contacting the inner wall of the housing body 102 and providing a drag force against further rotational speed. Some of the high pressure fluid from the regulating passage 118 leaks past and provides some lubrication to the segments 122a. This leakage fluid then exits through the discharge ports 126 through the housing body 102.
This nozzle 150 is the same as that shown in
The following table illustrates this result:
The high pressure nozzle cylindrical housing body 102 and tubular shaft member 108 are preferably made of a high strength stainless steel. Each of the partial annular weight segments in the embodiments described herein is preferably made of a non-galling metal or a metal coated with an anti-galling material to prevent galling of the segment against the rail 124 or the inner surface of the cylindrical housing body 102. One such non-galling metal is 660 Bronze, which was used in the above example and in the embodiments described below.
Many changes may be made to the rotary nozzle assembly described above without departing from the scope of the present disclosure. For example, the weighted segments may be three, four or five or more partial annular segments wherein at least two are restrained by a radially extending rail such that the segments cannot rotate about the shaft member and can only move outward radially as the shaft member rotates about the central passage. The rail 124 and/or ribs 128 may be other than as specifically shown. For example, the rail 124 may include discrete tabs rather than continuous ribs. The rail 124 may have a dovetail cross-sectional shape rather than utilizing a raised rib or ridge 128 at right angles as illustrated to prevent axial movement of the segments 122 or 122a along the rail 124.
A first exemplary alternative configuration 122b of a weight segment 122 is shown in
A second exemplary alternative configuration 122c of a weight segment 122 in accordance with the present disclosure is shown in
A third exemplary alternative configuration of a weight segment 122d in accordance with the present disclosure is shown in
Another variation is shown in
A fourth exemplary alternative configuration of a weight segment 122f in accordance with the present disclosure is shown in
An end view of the segment 122f is shown in
A fifth alternative embodiment of a weight segment 122g is shown in an end view in
Again, as the shaft 108 rotates, centrifugal force pushes the segments 122g radially outward along the rail 124, eventually contacting the inner wall of the housing body 102 and exerting a drag force against the inner wall of the housing body 102 thereby reducing further rotational speed. Some of the high pressure fluid from the regulating passage 118 leaks past and provides some lubrication to the segments 122g. This leakage fluid then exits through the discharge ports 126 through the housing body 102. Each of the segments 122g has an inner diameter larger than the inlet end 110 of the shaft 108 toward the inlet end 110 so as to form an annular recess 190 around the shaft 108 at the inlet end 110 when both semi annular segments are mounted to the shaft 108 together on the rail 124. Each of the segments 122g may also be provided with peripheral annular grooves 132 and slanted axial grooves 170-180 as in the embodiment described above with reference to
Many variations and combinations may be made to the above various embodiments of the retarding partial annular weight segments 122a-g described above. For example, in the weight segments 122a shown in
This application claims the benefit of priority of U.S. Provisional patent application Ser. No. 63/070,953 filed Aug. 27, 2020, entitled Self Regulating Fluid Bearing High Pressure Rotary Retarder Nozzle, and the benefit of priority of U.S. Provisional Patent Application Ser. No. 63/159,666, filed Mar. 11, 2021, having the same title.
Number | Date | Country | |
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63070953 | Aug 2020 | US | |
63159666 | Mar 2021 | US |